The present invention relates to air cushion units for stopping bleeding at wounds after arterial puncture.
This invention is an improvement of the devices disclosed in PCT/SE93/00705 and U.S. Pat. No. 5,542,427.
The replaceable unit according to these disclosures, which is for single use, includes a base plate, the upper side of which is attached to the arch of a femoral compressor, such as the one disclosed in EP-0 462 088, assigned to the present applicant. The attaching is done by means of a xe2x80x9csnap attachmentxe2x80x9d.
On the base plate there is an inflatable air cushion which is mounted by gluing or fusing along the base plate""s periphery. The material which the cushion is made of is, seen from a cross sectional view, folded so that the air cushion when not inflated, that is, as it is packaged, takes up as little volume as possible.
Along the periphery of the base plate there is a groove. Melt-glue is placed in the groove and after heat and pressure treatment in a manner well known to the skilled person, this makes for an airtight sealing of the air cushion against the base plate.
A problem with the prior art air cushion units is that they do not exert the desired centered and axially directed pressure during the entire pressure treatment. Especially during the pressurising and depressurising phases, it may happen that one of the folds in the air cushion forms a circular rim extending beyond the contact surface. Also, during pressurising and depressurising the top portion of the cushion may invert and thereby exerts less pressure in the central compression area. These phenomena causes the entire unit to press not on the wound but instead on a circular path around the wound. This obviously may cause unnecessary bleeding, since there is nothing pressing properly against the wound, or at least not to a sufficient extent. It may also happen that it is no longer possible to actually be able to pressurise the cushion sufficiently to obtain the necessary contact at the wound, in that the cushion does not expand any further. In such circumstances the entire device may be rendered at least partially ineffective.
An object of the present invention is therefore to provide an improved air cushion unit, that sits steadily on the wound site and as desired, exerts a centered and axially directed pressure during the entire compression period, such that the risk of inverting of the cushion is eliminated. Also, the risk for rebleeding should be eliminated.
This object is achieved by providing an air cushion unit, preferably of a single use type, for use together with a femoral compressor. The air cushion unit, which is attached to the arch of the femoral compressor, has a base plate and an inflatable air cushion attached to the base plate. The air cushion is characterised by being reinforced over an area of contact against a wound site.
Preferably said reinforcement is achieved by providing reinforcement elements in the form of ribs or ridges in a star configuration on the inside of the air cushion, supporting the entire area of contact.
In a particularly preferred embodiment said reinforcement elements have a shape corresponding to a circular segment and are laid out in a star configuration.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.